experimental UI: only wrap lines if curses are used

Lines are wrapped in the progress bar to reliably know how many
lines we'll eventually have to erase (there are a couple of reasons
for this; for example, the information about the terminal width often
is unreliable). So, if we don't erase lines anyway, we can as well let
the terminal break lines.

--
Change-Id: Id20806e6d53bfeccc781200eeac96acf48a74b1d
Reviewed-on: https://bazel-review.googlesource.com/#/c/3292
MOS_MIGRATED_REVID=119510906

2 files changed, 16 insertions, 4 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalEventHandler.java b/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalEventHandler.java
index e13b75b834..e4b0128e3a 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalEventHandler.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/ExperimentalEventHandler.java
@@ -27,6 +27,7 @@ import com.google.devtools.build.lib.pkgcache.LoadingPhaseCompleteEvent;
 import com.google.devtools.build.lib.skyframe.LoadingPhaseStartedEvent;
 import com.google.devtools.build.lib.util.Clock;
 import com.google.devtools.build.lib.util.io.AnsiTerminal;
+import com.google.devtools.build.lib.util.io.AnsiTerminalWriter;
 import com.google.devtools.build.lib.util.io.LineCountingAnsiTerminalWriter;
 import com.google.devtools.build.lib.util.io.LineWrappingAnsiTerminalWriter;
 import com.google.devtools.build.lib.util.io.OutErr;
@@ -243,10 +244,14 @@ public class ExperimentalEventHandler extends BlazeCommandEventHandler {
   }
 
   private void addProgressBar() throws IOException {
-    LineCountingAnsiTerminalWriter terminalWriter = new LineCountingAnsiTerminalWriter(terminal);
-    stateTracker.writeProgressBar(
-        new LineWrappingAnsiTerminalWriter(terminalWriter, terminalWidth - 1));
+    LineCountingAnsiTerminalWriter countingTerminalWriter =
+        new LineCountingAnsiTerminalWriter(terminal);
+    AnsiTerminalWriter terminalWriter = countingTerminalWriter;
+    if (cursorControl) {
+      terminalWriter = new LineWrappingAnsiTerminalWriter(terminalWriter, terminalWidth - 1);
+    }
+    stateTracker.writeProgressBar(terminalWriter);
     terminalWriter.newline();
-    numLinesProgressBar = terminalWriter.getWrittenLines();
+    numLinesProgressBar = countingTerminalWriter.getWrittenLines();
   }
 }
diff --git a/src/test/shell/integration/experimental_ui_test.sh b/src/test/shell/integration/experimental_ui_test.sh
index df8e6c84c1..e411b53904 100755
--- a/src/test/shell/integration/experimental_ui_test.sh
+++ b/src/test/shell/integration/experimental_ui_test.sh
@@ -80,6 +80,13 @@ function test_basic_progress_no_curses() {
   expect_log $'\x1b\[32m'
 }
 
+function test_no_curses_no_linebreak() {
+  bazel test --experimental_ui --curses=no --color=yes --terminal_columns=9 \
+    pkg:true 2>$TEST_log || fail "bazel test failed"
+  # expect a long-ish status line
+  expect_log '\[[0-9,]* / [0-9,]*\]......'
+}
+
 function test_pass() {
   bazel test --experimental_ui --curses=yes --color=yes pkg:true >$TEST_log || fail "bazel test failed"
   # PASS is written in green on the same line as the test target